Since its inception in 1972 the biennial Gordon Research Conference on Microbial Toxins and Pathogenicity has formed a prime focal point for researchers studying microbial pathogenicity and related subjects. Recent advances in understanding the mode of action of known toxins at the molecular level, the identification of new toxins and virulence factors and the application of new genetic, biochemical and immunological techniques to basic questions of pathogenic mechanisms have made this area one of the most exciting in modern biology. The 1986 Conference will focus on recent advances in the study of microbial pathogenic mechanisms at the molecular level. Eight plenary sessions are planned on the following rapidly evolving topics: structure and function of bacterial protein toxins, genetics and regulation of bacterial protein toxins, toxin receptors and internalization, endotoxin, bacterial pili and attachment, antigenic variation of bacterial surface proteins, microbial invasion and intracellular survival, and molecular analysis of selected microbial surface antigens. Dr. Ruth Nussenzweig will present the honorary lectureship on "Molecular Approaches to Vaccines for Malaria." Poster sessions will complement the plenary sessions, and there will be ample opportunities for informal discussions among participants.